CHRPAK
Strings and Characters

CHRPAK is a C library which can handle characters and strings.

CHRPAK began when I simply wanted to be able to capitalize a string. Now it has expanded to a number of interesting uses. Many unusual situations are provided for, including

• string '31.2' <=> numeric value 31.2;
• uppercase <=> lowercase;
• removal of control characters or blanks;
• sorting, merging, searching.

Many of the routine names begin with the name of the data type they operate on:

• B4 - a 4 byte word;
• CH - a character;
• CHVEC - a vector of characters;
• DEC - a decimal fraction;
• DIGIT - a character representing a numeric digit;
• I4 - an integer;
• R4 - a real;
• R8 - a double precision real;
• RAT - a ratio I/J;
• S - a string;
• SVEC - a vector of strings;
• SVECI - a vector of strings, implicitly capitalized;

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

CHRPAK is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Software and Data:

CAESAR, a C library which can apply a Caesar Shift Cipher to a string of text.

ROT13, a C program which makes a copy of a file which has been encoded using the ROT13 coding, and a ROT5 coding for digits.

Reference:

1. Carl Branden, John Tooze,
   Introduction to Protein Structure,
   Second Edition,
   Garland Publishing, 1999,
   ISBN: 0815323050,
   LC: QP551.B7635.
2. Paul Bratley, Bennett Fox, Linus Schrage,
   A Guide to Simulation,
   Second Edition,
   Springer, 1987,
   ISBN: 0387964673,
   LC: QA76.9.C65.B73.
3. IEEE Standards Committee 754,
   IEEE Standard for Binary Floating Point Arithmetic,
   ANSI/IEEE Standard 754-1985,
   SIGPLAN Notices,
   Volume 22, Number 2, 1987, pages 9-25.
4. Donald Knuth,
   The Art of Computer Programming,
   Volume 3, Sorting and Searching,
   Second Edition,
   Addison Wesley, 1998,
   ISBN: 0201896850,
   LC: QA76.6.K64.
5. Albert Nijenhuis, Herbert Wilf,
   Combinatorial Algorithms for Computers and Calculators,
   Academic Press, 1978,
   ISBN: 0-12-519260-6,
   LC: QA164.N54.

Source Code:

• chrpak.c, the source code;
• chrpak.h, the include file;

Examples and Tests:

• chrpak_test.c, the calling program;
• chrpak_test.txt, the output file.

List of Routines:

• A_TO_I4 returns the index of an alphabetic character.
• BASE_TO_I4 returns the value of an integer represented in some base.
• BYTE_TO_INT converts 4 bytes into an unsigned integer.
• CH_CAP capitalizes a single character.
• CH_COUNT_CVEC_ADD adds a character vector to a character count.
• CH_EQI is TRUE (1) if two characters are equal, disregarding case.
• CH_INDEX_FIRST finds the first occurrence of a character in a string.
• CH_INDEX_LAST finds the last occurrence of a character in a string.
• CH_IS_ALPHA is TRUE if a charaacter is alphabetic.
• CH_IS_ALPHANUMERIC is TRUE if a character is alphanumeric.
• CH_IS_CONTROL is TRUE if a character is a control character.
• CH_IS_DIGIT returns TRUE if a character is a decimal digit.
• CH_IS_LOWER is TRUE if C is a lowercase alphabetic character.
• CH_IS_SPACE is TRUE if a character represents "white space".
• CH_LOW lowercases a single character.
• CH_READ reads one character from a binary file.
• CH_ROMAN_TO_I4 returns the integer value of a single Roman digit.
• CH_SCRABBLE returns the character on a given Scrabble tile.
• CH_SCRABBLE_FREQUENCY returns the Scrabble frequency of a character.
• CH_SCRABBLE_POINTS returns the Scrabble point value of a character.
• CH_SCRABBLE_SELECT selects a character with the Scrabble probability.
• CH_SWAP swaps two characters.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• CH_TO_DIGIT_BIN returns the integer value of a binary digit.
• CH_TO_ROT13 converts a character to its ROT13 equivalent.
• CH_TO_SCRABBLE returns the Scrabble index of a character.
• CH_UNIFORM returns a random character in a given range.
• DIGIT_INC increments a decimal digit.
• DIGIT_TO_CH returns the character representation of a decimal digit.
• HEX_DIGIT_TO_I4 converts a hexadecimal digit to an I4.
• I4_HUGE returns a "huge" I4.
• I4_LOG_10 returns the integer part of the logarithm base 10 of an I4.
• I4_MAX returns the maximum of two I4's.
• I4_MIN returns the smaller of two I4's.
• I4_SWAP switches two I4's.
• I4_TO_A returns the I-th alphabetic character.
• I4_TO_AMINO_CODE converts an integer to an amino code.
• I4_TO_HEX_DIGIT converts a (small) I4 to a hexadecimal digit.
• I4_TO_ISBN converts an I4 to an ISBN digit.
• I4_TO_MONTH_ABB returns an abbreviated month name.
• I4_TO_MONTH_NAME returns a month name.
• I4_TO_S converts an I4 to a string.
• I4_UNIFORM returns a scaled pseudorandom I4.
• ISBN_TO_I4 converts an ISBN character into an I4.
• R4_NINT returns the nearest integer to an R4.
• R8_UNIFORM_01 returns a unit pseudorandom R8.
• S_ADJUSTL flushes a string left.
• S_BEGIN reports whether string 1 begins with string 2.
• S_BLANK_DELETE removes blanks and left justifies the remainder.
• S_BLANKS_DELETE replaces consecutive blanks by one blank.
• S_CAP capitalizes all the characters in a string.
• S_CAT concatenates two strings to make a third string.
• S_CH_COUNT counts occurrences of a particular character in a string.
• S_CH_DELETE removes all occurrences of a character from a string.
• S_CONTROL_BLANK replaces control characters with blanks.
• S_EQI reports whether two strings are equal, ignoring case.
• S_ESCAPE_TEX de-escapes TeX escape sequences.
• S_FIRST_CH points to the first occurrence of a character in a string.
• S_FIRST_NONBLANK points to the first nonblank character in a string.
• S_INDEX_LAST_C points to the last occurrence of a given character.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_LOW replaces all uppercase characters by lowercase ones.
• S_NEWLINE_TO_NULL replaces carriage returns or newlines by nulls.
• S_REPLACE_CH replaces all occurrences of one character by another.
• S_REVERSE reverses the characters in a string.
• S_SCRABBLE_POINTS returns the Scrabble point value of a string.
• S_SORT_A sorts a string into ascending order.
• S_SUBSTRING returns a substring of a given string.
• S_TO_I4 reads an I4 from a string.
• S_TO_I4VEC reads an I4VEC from a string.
• S_TO_L4 reads an L4 from a string.
• S_TO_R4 reads an R4 value from a string.
• S_TO_R4VEC reads an R4VEC from a string.
• S_TO_R8 reads an R8 value from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_TO_ROT13 "rotates" the alphabetical characters in a string by 13 positions.
• S_TRIM promotes the final null forward through trailing blanks.
• S_WORD_CAP capitalizes the first character of each word in a string.
• S_WORD_COUNT counts the number of "words" in a string.
• S_WORD_EXTRACT_FIRST extracts the first word from a string.
• SORT_HEAP_EXTERNAL externally sorts a list of items into ascending order.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the C source codes.